9.991 stderr

stderr is created in 32-bit mode instead of 64-bit mode: Cygwin 1.5.x.
One workaround is to use freopen(NULL, “r+”, stderr) on Cygwin 1.5.21
or newer. Another is to use the gnulib ftello module and do
ftello(stderr).

POSIX states that a setuid application can guarantee that fd 2 is
open, but some systems guarantee this even for non-setuid programs.
If an application is executed with fd 2 closed, use of stderr
can affect an unrelated file that happened to be assigned to fd 2.
The gnulib *-safer modules may be used to guarantee that fd 2 stays
reserved for stderr.